Image pickup lens, image pickup apparatus and mobile terminal

ABSTRACT

Provided is a small-sized five-element image pickup lens which ensures a sufficient lens speed of about F2 and exhibits various aberrations being excellently corrected. The image pickup lens is composed of, in order from the object side, a first lens with a positive refractive power, including a convex surface facing the object side; a second lens with a negative refractive power, including a concave surface facing the image side; a third lens with a positive or negative refractive power; a fourth lens with a positive refractive power, including a convex surface facing the image side; and a fifth lens with a negative refractive power, including a concave surface facing the image side. The image-side surface of the fifth lens has an aspheric shape, and includes an inflection point at a position excluding an intersection point with the optical axis.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of U.S. patent application Ser. No.13/059,501 which was filed with the U.S. Patent and Trademark Office onFeb. 17, 2011 now U.S. Pat. No. 8,035,723 and which is a U.S. NationalPhase application of International Application PCT/JP2009/064634 filedAug. 21, 2009. Foreign priority is claimed for this invention andapplication, corresponding application(s) having been filed in Japan onAug. 25, 2008, No. 2008-215162, Japan on Feb. 26, 2009, No. 2009-043786.

TECHNICAL FIELD

The present invention relates to a small-sized image pickup lens withexcellent lens speed, used for a solid-state image pickup element suchas a CCD type image sensor or a CMOS type image sensor, and to an imagepickup apparatus equipped with the image pickup lens, and a mobileterminal equipped with the image pickup apparatus.

BACKGROUND ART

Recently, a mobile terminal on which an image pickup apparatus employinga solid-state image pickup element such as a CCD type image sensor or aCMOS type image sensor is mounted are coming into wide use. As for animage pickup apparatus to be mounted on such a mobile terminal, thoseemploying an image pickup element with a large number of pixels havebeen supplied into the market in order to obtain images with higherimage quality. Image pickup elements with a larger number of pixels werelarge in size. However, corresponding to the recent progress of pixelsin terms of minuteness, image pickup elements have been becomingsmall-sized recently.

An image pickup lens used for such the image pickup elements withminuteness is required to have high resolving power. However, theresolving power is limited depending on F-number, and it is becomingdifficult to give sufficient performance with a conventional art withF-number of about F2.8. Therefore, image pickup lenses with excellentlens speed of about F2, suitable for a small-sized image pickup lenswith a large number of pixels has been required, because a lens withsmaller F-number and more excellent lens speed exhibits higher resolvingpower. As an image pickup lens for such the use, there has been proposeda five-element image pickup lens that can make the aperture diameterlarger and make its performance higher than a lens having athree-or-four-element structure.

As a five-element image pickup lens, there has been known an imagepickup lens composed of, in order from the object side, the front groupcomposed of the first lens with positive or negative refractive powerand the second lens with positive refractive power, an opening aperture,and a rear group composed of a third lens with negative refractivepower, a fourth lens with positive refractive power, and a fifth lenswith positive or negative refractive power (For example, see PatentLiterature 1 and Patent Literature 2).

Further, there has been known a four-element image pickup apparatus withlens speed of about F2 (For example, Patent Literature 3).

CITATION LIST Patent Literature

-   -   Patent Literature 1: JP-A No. 2007-279282    -   Patent Literature 2: JP-A No. 2006-293042    -   Patent Literature 3: JP-A No. 2007-322844

SUMMARY OF INVENTION Technical Problem

However, in the image pickup lens written in the above Patent Literature1, a front group is composed of spherical systems. When the lens has asmall light speed of about F2, correction of spherical aberration andcoma is insufficient and excellent performance is hardly maintained.Further, because it has a structure that both of the front group and therear group have positive refractive power, a position of the principalpoint of the optical system is located at a closer position to the imageand the back focal length becomes longer, compared with the structuresuch as a telephoto type in which the rear group has negative refractivepower. Therefore, the total length of the image pickup lens (the lengthalong the optical axis from the first surface at the closest position tothe object side to the image plane) is elongated, which is a problem.

Further, the image pickup lens described in the above-described PatentLiterature 2, has a lens speed of about F2. However, it has a structurethat the both of the first lens and he second lens have positiverefractive power, and chromatic aberration correction is insufficient inthe front group. Further, because it has a structure that the both ofthe front group and the rear group has positive refractive powersimilarly to Patent Literature 1, and the rearmost lens is a positivelens, the total length of the image pickup lens is elongated, which is aproblem.

Furthermore, the image pickup lens described in Patent Literature 3 hasa lens speed of about F2. However, aberration correction is insufficientbecause it is a four-element structure, and it is hard to say that it issuitable for an image pickup lens coping with an increase of the pixelnumbers.

The present invention is achieved in view of the above problems, and isaimed to obtain a small-sized five-element image pickup lens which hassufficient lens speed of about F2 and exhibits excellently-correctedvarious aberrations, and to provide an image pickup apparatus by whichpreferable photographed images with high image quality can be obtainedby the image pickup lens provided therein, and a mobile terminalequipped with the image pickup apparatus. As for a dimension of asmall-sized image pickup lens, the present invention is aimed to achievedownsizing at the level satisfying the following expression (10).Satisfying the range allows to downsize and lighten the whole imagepickup apparatus.L/2Y<1.1  (10)

In the expression, L represents a distance along the optical axis fromthe lens surface arranged at the closest position to the object side inthe total system of the image pickup lens to the focal point at theimage side, and 2Y represents a diagonal length of an image pickupsurface of a solid-state image pickup element (a diagonal length of arectangular effective pixel area of the solid-state image pickupelement).

In the above description, “focal point at the image side” means an imagepoint formed when a parallel ray which is parallel with the optical axisenters a lens.

When there is arranged a parallel flat plate such as an optical low-passfilter, an infrared blocking filter and a sealing glass of a solid-stateimage pickup element package, at a position between the lens surfacearranged at the closest position to the image side in the image pickuplens and the focal point at the image side, the value of L is calculatedon the assumption that a space of the parallel flat plate is regarded asan air-equivalent distance.

Solution to Problem

The above object will be achieved by the invention which will bedescribed below.

An image pickup lens of an item 1 is an image pickup lens for forming animage of a subject onto a photoelectric conversion section of asolid-state image pickup element. The image pickup lens is characterizedby comprising, in order from an object side thereof: a first lens with apositive refractive power, comprising a convex surface facing the objectside; a second lens with a negative refractive power, comprising aconcave surface facing an image side; a third lens with a positive ornegative refractive power; a fourth lens with a positive refractivepower, comprising a convex surface facing the image side; and a fifthlens with a negative refractive power, comprising a concave surfacefacing the image side, wherein an image-side surface of the fifth lenshas an aspheric shape, and includes an inflection point at a positionexcluding an intersection point with an optical axis.

According to an embodiment of the invention as in item 1, by forming twoor three lenses in the five-element structure into negative lenses, thenumber of surfaces having divergent function is increased to makecorrection of Petzval sum easy, which allows to obtain an image pickuplens maintaining an excellent image-forming function up to theperipheral portion of an image area.

Further, by forming the image-side surface of the fifth lens arranged atthe closest position to the image side into an aspheric surface, variousaberrations can be corrected in an excellent condition at the peripheralportion of the image area. Further, by forming the surface into anaspheric shape including an inflection point at a position thereonexcept the intersection with the optical axis, telecentricity of a lightflux at the image side can be easily secured.

Further, by forming positive composite power with the first to fourthlenses, and forming negative power with the fifth lens, there can beprovided so-called a telephoto-type lens construction which isadvantageous to downsize the total length of the image pickup lens.

In the present specification, “an inflection point” is a point on anaspheric surface at which a tangential plane at a peak of the asphericsurface is perpendicular to the optical axis, in a curve of sectionalshape of the lens within an effective radius.

An image pickup lens of an item 2 is an image pickup lens according toitem 1, characterized by satisfying the following conditionalexpression.0.9<f12/f<2.0  (1)

In the expression, f12 is a composite focal length of the first lens andthe second lens, and f is a focal length of a total system of the imagepickup lens.

The conditional expression (1) is a conditional expression for definingthe composite focal length of the first lens and the second lensproperly.

When the value of the conditional expression (1) becomes lower than theupper limit, the positive composite focal length of the first lens andthe second lens can be properly maintained. Thereby, the principal pointof the entire system can be placed at a closer position to the objectside, and the total length of the image pickup lens can be shortened. Onthe other hand, when the value becomes larger than the lower limit, thepositive composite focal length of the first lens and the second lensdoes not become excessively small. Thereby, higher-order sphericalaberrations and coma can be controlled to be small, and fluctuation ofan image plane corresponding to manufacturing error can be reduced.

An image pickup lens of an item 3 is an image pickup lens according toitems 1 or 2, characterized by satisfying the following conditionalexpressions.−2.5<f2/f<−1.0  (2)0.3<r4/f<0.7  (3)

In the expressions, f2 is a focal length of the second lens, r4 is acurvature radius of an image-side surface of the second lens, and f is afocal length of a total system of the image pickup lens.

The conditional expression (2) is a conditional expression fordetermining the focal length of the second lens properly. When the valueof the conditional expression (2) becomes lower than the upper limit,the negative refractive power of the second lens does not excessivelystrong, and coma and distortion can be reduced in the peripheralportion. On the other hand, when the value becomes larger than the lowerlimit, the negative refractive power of the second lens can bemaintained properly, which is effective for reducing Petzval sum andcorrecting field curvature.

Further, it is more preferable that the following conditional expressionis satisfied.−2.4<f2/f<−1.0  (2)′

Further, the conditional expression (3) is a conditional expression fordetermining the curvature radius of the image-side surface of the secondlens properly. When the value of the conditional expression (3) becomeslower than the upper limit, the position of the principal point of thesecond lens moves at a closer position to the image side, which allowsreduction of Petzval sum and correction of field curvature, withoutmaking the focal length of the second lens excessively greater. On theother hand, when the value becomes larger than the lower limit, anincident angle of a ray at the periphery of the image-side surface ofthe second lens becomes small, and generation of coma can be controlled.

Further, it is more preferable that the following conditional expressionis satisfied.0.35<r4/f<0.65  (3)′

An image pickup lens of an item 4 is an image pickup lens according toitems 1, 2 or 3, characterized by satisfying the following conditionalexpression.20<ν1−ν2<70  (4)

In the expression, v1 is an Abbe number of the first lens, and v2 is anAbbe number of the second lens.

The conditional expression (4) is a conditional expression forcorrecting chromatic aberrations of the total system of the image pickuplens properly. When the value of the conditional expression (4) becomeslarger than the lower limit, chromatic aberrations such as alongitudinal chromatic aberration and a chromatic aberration ofmagnification can be corrected in a balanced condition. On the otherhand, when the value becomes lower than the upper limit, the imagepickup lens can be formed of materials which are easily available.

Further, it is more preferable that the following conditional expressionis satisfied.25<v1−v2<65  (4)′

An image pickup lens of an item 5 is an image pickup lens according toitems 1-4, characterized by satisfying the following conditionalexpression.1.60<n2<2.10  (5)

In the expression, n2 is a refractive index of the second lens ford-line.

The conditional expression (5) is a conditional expression forcorrecting chromatic aberrations and field curvature of the total systemof the image pickup lens properly. When the value of the conditionalexpression (5) becomes larger than the lower limit, refractive power ofthe second lens which has a relatively large dispersion can bemaintained properly, and chromatic aberrations and field curvature canbe corrected properly. On the other hand, when the value becomes lowerthan the upper limit, the image pickup lens can be formed of materialswhich are easily available.

Further, it is more preferable that the following conditional expressionis satisfied.1.60<n2<2.00  (5)′

An image pickup lens of an item 6 is an image pickup lens according toitems 1-5, characterized by satisfying the following conditionalexpression.−2.35<Pair23/P<−0.75  (6)

In the expression, P is a refractive power of the total system of theimage pickup lens, and Pair23 is a refractive power of so-called an airlens formed by an image-side surface (r4) of the second lens and anobject-side surface of the third lens (r5), wherein the refractive poweris a reciprocal of a focal length and the value of Pair23 is calculatedby the following expression (7).Pair23={(1−n2)/r4}+{(n3−1)/r5}−{(1−n2)·(n3−1)·d23/(r4·r5)}  (7)

In the expression, n2 is a refractive index of the second lens ford-line, n3 is a refractive index of the third lens for d-line, r4 is acurvature radius of the image-side surface of the second lens, r5 is acurvature radius of the object-side surface of the third lens, and d23is an air distance along the optical axis between the second lens andthe third lens.

The conditional expression (6) is a conditional expression fordetermining the refractive power of the air lens formed by theimage-side surface of the second lens and the object-side surface of thethird lens properly. Because the value of the conditional expression (6)becomes lower than the upper limit, a negative refractive power of theair lens can be maintained properly. Thereby, Petzval sum does notexcessively large and an image plane can be made flat, and chromaticaberrations can be corrected in an excellent condition. On the otherhand, when the value becomes larger than the lower limit, the negativerefractive power of the air lens does not become excessively strong.Thereby, the curvature radiuses of the image-side surface of the secondlens and the object-side surface of the third lens can be made large,which enhances productivity of the lenses. Further, because theimage-side surface of the second lens and the object-side of the thirdlens are positioned to be separated away from each other in the off-axisportion, which enables to secure space where a light-sealing member forpreventing unnecessary light such as ghost is inserted between thesecond lens and the third lens, without enlarging the distance along theoptical axis between those lenses.

Further, it is more preferable that the following conditional expressionis satisfied.−2.25<Pair23/P<−0.85  (6)′

An image pickup lens of an item 7 is an image pickup lens according toitems 1-6, characterized by satisfying the following conditionalexpressions.1.5<|f3|/f<20.0  (8)0.2<d456/f<0.4  (9)

In the expressions, f3 is a focal length of the third lens, d456 is adistance along the optical axis between an image-side surface of thesecond lens and an object-side surface of the fourth lens, and f is afocal length of a total system of the image pickup lens.

The conditional expression (8) is a conditional expression fordetermining the focal length of the third lens properly. The third lenscorresponds to a lens with a small refractive power for correcting theimage plane, arranged at a position between a second lens and a thirdlens in a conventional four-element structure lens. When the value ofthe conditional expression (8) becomes lower than the upper limit, theimage plane can be corrected more effectively than the four-elementstructure lens. On the other hand, when the value becomes larger thanthe lower limit, a variation of a focal length of the total systemcaused by an increase of the refractive power of the third lens can becontrolled.

Further, the conditional expression (9) is a conditional expression fordetermining the distance between the second lens and the fourth lensproperly. When the value of the conditional expression (9) becomeslarger than the lower limit, a proper distance for positioning the thirdlens for correcting the image plane can be maintained. On the otherhand, when the value becomes lower than the upper limit, an increase ofthe total length caused by an increase of the distance between thesecond lens with negative refractive power and the fourth lens withpositive refractive power can be controlled.

An image pickup lens of an item 8 is an image pickup lens according toitems 1-7, characterized in that an object-side surface of the thirdlens is formed in an aspheric shape which curves to be closer to thesecond lens at a position on the surface, as the position advancestoward a peripheral portion.

By forming the object-side surface of the third lens in an asphericshape which curves to be closer to the second lens at a closer positionto a peripheral portion, the second lens and the third lens forms asymmetric shape across an air gap, which corrects coma caused in thesecond lens and the third lens in an excellent condition. Further, itforms a structure which easily corrects a chromatic aberration ofmagnification and distortion of the total system of the image pickuplens.

An image pickup lens of an item 9 is an image pickup lens according toitems 1-8, characterized in that an image-side surface of the secondlens is formed in an aspheric shape having negative refractive powerwhich becomes smaller at a position on the surface, as the positionbecomes more distant from an optical axis toward a peripheral portion.

By forming the image-side surface of the second lens in an asphericshape having negative refractive power which becomes smaller at aposition being more distant from the optical axis toward the peripheralportion, a ray does not excessively deflect in the peripheral portionand excellent telecentricity can be maintained in the peripheralportion.

An image pickup lens of an item 10 is an image pickup lens according toitems 1-9, characterized in that an image-side surface of the fourthlens is formed in an aspheric shape having positive refractive powerwhich becomes smaller at a position on the surface, as the positionbecomes more distant from an optical axis toward a peripheral portion.

By forming the image-side surface of the fourth lens in an asphericshape having positive refractive power which becomes smaller at aposition being more distant from an optical axis toward a peripheralportion, excellent telecentricity can be maintained in the peripheralportion. Further, the image-side surface of the second lens is notrequired to have excessively weak negative refractive power, andoff-axis aberrations can be corrected in an excellent condition.

An image pickup lens of an item 11 is an image pickup lens according toitems 1-10, characterized by further comprising an aperture stop whichis arranged at a position being closer to the image side than a positionon the optical axis of an object-side surface of the first lens andbeing closer to the object side than a position in a most peripheralportion of the object-side surface of the first lens.

When the aperture stop is positioned at a position which is rear fromthe position on the optical axis on the object-side surface of the firstlens and is front of the peripheral portion of the surface, a refractionangle at the object-side surface of the first lens can be reduced.Therefore, generation of the higher-order spherical aberrations and comacaused in the first lens can be controlled. Further, the height of a raypassing through the first lens can be lowered, thereby, the edgethickness of the first lens is easily secured and moldability can beenhanced.

An image pickup lens of an item 12 is an image pickup lens according toitems 1-11, characterized in that each of the first through fifth lensesis formed of a plastic material.

In recent years, under the purpose of downsizing of an overallsolid-state image pickup apparatus, there has been developed asolid-state image pickup element with a smaller pixel pitch, resultingin downsizing of an image pickup surface, compared with anothersolid-state image pickup element having the same number of pixels. Inthe image pickup lens for the solid-state image pickup element having asmall-sized image pickup surface of this kind, a focal length of thetotal optical system is requested to be relatively short, which makes acurvature radius and the outside diameter of each lens to beconsiderably small. Therefore, when compared with a glass lensmanufactured through time-consuming grinding processing, image pickuplenses in which all lenses are plastic lenses manufactured by injectionmolding can be mass-produced at low cost even if each lens has a smallcurvature radius and a small outside diameter. In addition, it ispossible to control wear and tear of a molding die because presstemperature can be made low in the case of a plastic lens, and afrequency of replacement of molding dies and a frequency of maintenancecan be reduced, which realizes cost reduction.

An image pickup apparatus of an item 13 is characterized by comprising:a solid-state image pickup element for photo-electrically converting animage of a subject; and the image pickup lens described in accordancewith items 1-12 Thereby, there can be obtained an image pickup apparatusby which excellent shots with high image quality can be obtained.

A mobile terminal of an item 14 is characterized by comprising an imagepickup apparatus as in item 13. Thereby, there can be obtained a mobileterminal equipped with an image pickup apparatus by which excellentshots with high image quality can be obtained.

Advantageous Effects of Invention

According to the present invention, there can be provided a small-sizedfive-element image pickup lens which ensures a sufficient lens speed ofabout F2 and exhibits various aberrations being excellently corrected,and an image pickup apparatus and mobile terminal by which excellentshots with high image quality can be obtained.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a perspective view illustrating an example of an imagepickup apparatus relating to the present embodiment.

FIG. 2 shows outline views of a cell phone which is an example of amobile terminal equipped with an image pickup apparatus relating to thepresent embodiment.

FIG. 3 shows an example of a control block diagram of a cell phone.

FIG. 4 shows a sectional view of the image pickup lens of Example 1.

FIG. 5 shows aberration diagrams of the image pickup lens of Example 1(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 6 shows a sectional view of the image pickup lens of Example 2.

FIG. 7 shows aberration diagrams of the image pickup lens of Example 2(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 8 shows a sectional view of the image pickup lens of Example 3.

FIG. 9 shows aberration diagrams of the image pickup lens of Example 3(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 10 shows a sectional view of the image pickup lens of Example 4.

FIG. 11 shows aberration diagrams of the image pickup lens of Example 4(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 12 shows a sectional view of the image pickup lens of Example 5.

FIG. 13 shows aberration diagrams of the image pickup lens of Example 5(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 14 shows a sectional view of the image pickup lens of Example 6.

FIG. 15 shows aberration diagrams of the image pickup lens of Example 6(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 16 shows a sectional view of the image pickup lens of Example 7.

FIG. 17 shows aberration diagrams of the image pickup lens of Example 7(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 18 shows a sectional view of the image pickup lens of Example 8.

FIG. 19 shows aberration diagrams of the image pickup lens of Example 8(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 20 shows a sectional view of the image pickup lens of Example 9.

FIG. 21 shows aberration diagrams of the image pickup lens of Example 9(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 22 shows a sectional view of the image pickup lens of Example 10.

FIG. 23 shows aberration diagrams of the image pickup lens of Example 10(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 24 shows a sectional view of the image pickup lens of Example 11.

FIG. 25 shows aberration diagrams of the image pickup lens of Example 11(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 26 shows a sectional view of the image pickup lens of Example 12.

FIG. 27 shows aberration diagrams of the image pickup lens of Example 12(spherical aberration, astigmatism, distortion, and meridional coma).

FIG. 28 shows a sectional view of the image pickup lens of Example 13.

FIG. 29 shows aberration diagrams of the image pickup lens of Example 13(spherical aberration, astigmatism, distortion, and meridional coma).

DESCRIPTION OF EMBODIMENTS

The present invention will be described below by using embodiments.However, the scope of the invention is not limited to them.

FIG. 1 is a cross-sectional view of an example of image pickup apparatus50 relating to the present embodiment. This figure schematicallyillustrates the cross-section taken along the optical axis of the imagepickup lens.

As shown in the figure, image pickup apparatus 50 includes CMOS typeimage pickup element 51 as the solid-state image pickup element havingphotoelectric conversion section 51 a; image pickup lens 10 for forminga subject image onto photoelectric conversion section 51 a of the imagepickup element 51; casing 53 as a lens barrel formed of a lightshielding member having an aperture section for the incident light fromthe object side; supporting substrate 52 a supporting image pickupelement 51; and flexible print substrate 52 b having an externalconnecting terminal 54 for sending and receiving electric signal. Theyare integrally formed in one body.

Image pickup element 51 includes photoelectric conversion section 51 arepresenting a light-receiving section, on the central portion of asurface on the light-receiving side of the image pickup element 51, andincludes signal processing circuit 51 b formed to surround thephotoelectric conversion section. On the photoelectric conversionsection 51 a, pixels (photoelectric conversion elements) are arranged ona two-dimensional basis. The signal processing circuit 51 b is composedof a drive circuit that obtains signal electric charges by drivingrespective pixels in succession, ND converting section that convertseach signal electric charge into digital signal and of a signalprocessing section that forms an output of image signal by using thedigital signal.

Around the outer edge of the light-receiving-side surface of imagepickup element 51, many pads which are not illustrated are provided andconnected with support substrate 52 a through bonding wires W. The imagepickup element 51 converts the signal charge from the photoelectricconversion section 51 a into image signal such as digital YUV signal,and outputs it to a predetermined circuit on the support substrate 52 athrough bonding wires W. Y represents luminance signal, U (=R−Y)represents color difference signal between red and the luminance signal,and V (=B−Y) represents color difference signal between blue and theluminance signal.

Hereupon, the image pickup element is not limited to the above-describedCMOS type image sensor, but another element such as a CCD can beemployed.

Substrate 52 is structured by hard support substrate 52 a supportingimage pickup element 51 and casing 53 on its one surface, and byflexible print substrate 52 b whose one end is connected to the othersurface (the opposite surface from image pickup element 51) of thesupport substrate 52 a. On the support substrate 52 a, many signaltransmission pads are provided on the both of the front and rearsurfaces. They are connected to image pickup element 51 through bondingwires W on the one surface, and are connected to the flexible printsubstrate 52 b on the other surface.

The flexible print substrate 52 b connects support substrate 52 a to anunillustrated external circuit (for example, a control circuit providedby the higher level of apparatus on which the image pickup apparatus ismounted), which enables to receive voltage and clock signal for drivingimage pickup element 51 from the external circuit and to output thedigital YUV signal to the external circuit.

Casing 53 is fixedly arranged on a surface of support substrate 52 awhich is a surface facing the image pickup element 51 so as to cover theimage pickup element 51. That is, one side of the casing 53 facing theimage pickup element 51 has a widely opened shape so as to surround theimage pickup element 51 and is contacted and fixed to the supportsubstrate 52 a. The other side of the casing 53 is formed in acylindrical shape having a flange with a small opening.

Inside casing 53, a parallel flat plate F having an infrared blockingfunction is fixedly arranged at a position between the image pickup lens10 and the image pickup element 51.

There are provided aperture stop S, first lens L1, second lens L2, thirdlens L3, fourth lens L4 and fifth lens L5, which are structured in sucha manner that a subject image is formed on photoelectric conversionsurface 51 a of image pickup element 51. Further, a one-dotted chainline represents the optical axis which is common in respective lensesL1-L5.

Lenses L1-L5 forming image pickup lens 10 are held by lens frame 55.Casing 53 houses this lens frame 55 and the image pickup lens 10 held bythe lens frame 55. The lens frame 55 is engaged with the casing 53 atits outer periphery, and is contacted with the flange section having asmall opening of the casing 53 to be positioned.

Further, although it is not illustrated, a fixed stop to cut unnecessarylight may be arranged in a space between lenses L1-L5. Generation ofghost and flare light can be suppressed when a rectangular fixed stop isarranged outside a path of a ray.

FIG. 2 shows outline views of cell phone 100 which is an example of amobile terminal equipped with image pickup apparatus 50.

In cell phone 100 shown in the figure, upper casing 71 as a caseprovided with the display screens D1 and D2, and lower casing 72provided with operation buttons 60 which is an input section, areconnected together through hinge 73. Image pickup apparatus 50 is housedbelow the display screen D2 in upper casing 71, and image pickupapparatus 50 is arranged in such a manner that light can be taken fromthe outer-surface side of upper casing 71.

This image pickup apparatus may also be arranged above the displayscreen D2 of upper casing 71 or on the side surface of upper casing 71.Further, it is naturally understood that the cell phone is not limitedto a folding type.

FIG. 3 is an example of a control block diagram of cell phone 100.

As shown in the figure, image pickup apparatus 50 is connected withcontrol section 101 of cell phone 100 through flexible printed board 52b, and outputs image signal such as luminance signal and colordifference signal to control section 101.

On the one hand, cell phone 100 is provided with: control section (CPU)101 which centrally controls each section and executes programscorresponding to various processing; operation buttons 60 which is aninput section for indicating and inputting the number; display screensD1 and D2 that display the predetermined data and images which aretaken; radio communication section 80 for realizing various kinds ofinformation communication to the external server; storage section (ROM)91 which stores system programs of the cell phone 100, variousprocessing programs, and necessary data such as terminal ID; andtemporary storage section (RAM) 92 which temporarily stores variousprocessing programs and data to be processed by control section 101,processed data, and image data from the image pickup apparatus 50 and isused as a working area.

Image signal inputted from image pickup apparatus 50 is stored innonvolatile storage section (flash memory) 93, is displayed on displayscreens D1 and D2, or is transmitted to the outside as image informationthrough radio communication section 80, by the control section 101 ofcell phone 100. Further, mobile cell phone 100 includes a microphone andspeaker for inputting and outputting voices, which are not illustrated.

EXAMPLES

Examples of the image pickup lens relating to the present invention willbe shown below. Symbols used in each example are as follows.

-   -   f: Focal length of the total system of the image pickup lens    -   fB: Back focal length    -   F: F-number    -   2Y: Diagonal length of an image pickup surface of the        solid-state image pickup element    -   ENTP: Position of an entrance pupil (distance from the first        surface to the position of the entrance pupil)    -   EXTP: Position of an exit pupil (distance from the image pickup        plane to the position of the exit pupil)    -   H1: Position of a front principal point (distance from the first        surface to the position of the front principal point)    -   H2: Position of a rear principal point (distance from the        rearmost surface to the position of the rear principal point)    -   r: Curvature radius    -   d: Surface distance on the optical axis    -   Nd: Refractive index of a lens material for d-line    -   νd: Abbe number of a lens material

In each example, a surface represented by a surface number followed byan asterisk “*” is a surface in an aspheric shape.

The shape of the aspheric surface is expressed by the following (Math.1), where the vertex of the surface is defined as the origin, X-axisextends along the optical axis direction, and h represents the height ina perpendicular direction to the optical axis.

$\begin{matrix}{X = {\frac{h^{2}/R}{1 + \sqrt{1 - {\left( {1 + K} \right){h^{2}/R^{2}}}}} + {\sum{A_{i}h^{i}}}}} & \left\lbrack {{Math}.\mspace{14mu} 1} \right\rbrack\end{matrix}$

In the expression, A_(i) is i-th-order aspheric surface coefficient, Ris a curvature radius, and K is a conic constant.

As for the aspheric surface coefficients, the power of 10 (for example,2.5×10⁻⁰²) will be expressed as by using “E” (for example, 2.5E−02).

Example 1

All the specifications of the image pickup lens of Example 1 are listedbelow.

-   f=5.65 mm-   fB=0.79 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.52 mm-   H1=−1.76 mm-   H2=−4.86 mm

Surface data of the image pickup lens of Example 1 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.40 1.37  2* 2.215 1.03 1.54470 56.2 1.44  3* −586.653 0.05 1.40  4*4.656 0.40 1.63200 23.4 1.38  5* 2.296 0.88 1.32  6* −8.258 0.52 1.6320023.4 1.41  7* −14.435 0.10 1.78  8* −7.418 1.48 1.54470 56.2 2.11  9*−1.387 0.41 2.39 10* −10.485 0.50 1.54470 56.2 2.73 11* 1.790 0.60 3.1512 ∞ 0.15 1.51630 64.1 3.45 13 ∞ 3.48

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.21857E+00, A4=0.29339E−03, A6=0.47203E−03, A8=−0.12988E−02,        A10=0.10888E−02, A12=−0.34643E−03, A14=0.34629E−04,        A16=0.40700E−06        Third Surface    -   K=0.30000E+02, A4=0.58273E−02, A6=0.18979E−02, A8=0.75933E−03,        A10=−0.13931E−03, A12=−0.46432E−03, A14=0.57197E−04,        A16=−0.20970E−05        Fourth Surface    -   K=0.63662E+01, A4=−0.40425E−01, A6=0.17426E−01, A8=−0.72085E−02,        A10=0.29070E−02, A12=−0.11301E−02, A14=−0.64825E−04        Fifth Surface    -   K=−0.42466E+01, A4=0.33662E−02, A6=0.17440E−01, A8=−0.91768E−02,        A10=0.71040E−02, A12=−0.14212E−02, A14=0.11035E−04        Sixth Surface    -   K=0.32082E+02, A4=−0.48243E−01, A6=−0.10597E−01, A8=0.53627E−02,        A10=0.30361 E−03, A12=0.77117E−03, A14=0.76282E−04        Seventh Surface    -   K=0.30000E+02, A4=−0.31204E−01, A6=0.35199E−03, A8=0.36759E−03,        A10=0.75107E−03, A12=0.11709E−03, A14=−0.63981E−04        Eighth Surface    -   K=0.19894E+01, A4=0.76139E−02, A6=0.30431E−02, A8=0.43518E−04,        A10=−0.11382E−03, A12=−0.65140E−05, A14=0.19280E−05        Ninth Surface    -   K=−0.39657E+01, A4=−0.42077E−01, A6=0.15382E−01,        A8=−0.27107E−02, A10=0.34375E−03, A12=−0.13909E−04,        A14=−0.13610E−05        Tenth Surface    -   K=0.61559E+01, A4=−0.43651E−01, A6=0.98617E−02, A8=−0.50206E−03,        A10=−0.19419E−03, A12=0.38080E−04, A14=−0.20420E−05        Eleventh Surface    -   K=−0.96030E+01, A4=−0.37012E−01, A6=0.71814E−02,        A8=−0.10214E−02, A10=0.83677E−04, A12=−0.41810E−05,        A14=0.10400E−06

Single lens data of the image pickup lens of Example 1 are listed below.

Lens Forefront surface Focal length (mm) 1 2 4.053 2 4 −7.672 3 6−31.566 4 8 2.882 5 10 −2.768

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 1 are listed below.f12/f=1.134  (1)f2/f=−1.357  (2)r4/f=0.406  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−2.093  (6)|f3|/f=5.583  (8)d456/f=0.265  (9)L/2Y=0.961  (10)

In Example 1, each of lenses is formed of a plastic material.

FIG. 4 shows a sectional view of the image pickup lens of Example 1. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 5 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 1.

Example 2

All the specifications of the image pickup lens of Example 2 are listedbelow.

-   f=5.73 mm-   fB=0.36 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.36 mm-   H1=−3.08 mm-   H2=−5.36 mm

Surface data of the image pickup lens of Example 2 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.39 1.39  2* 2.310 1.04 1.54470 56.2 1.45  3* −21.818 0.05 1.42  4*7.361 0.40 1.63200 23.4 1.40  5* 2.718 0.74 1.37  6* −8.295 0.89 1.5447056.0 1.47  7* −10.387 0.09 1.81  8* −15.009 1.19 1.54470 56.2 1.87  9*−2.234 0.90 2.21 10* −4.038 0.51 1.54470 56.2 2.64 11* 3.829 0.60 3.1412 ∞ 0.15 1.51630 64.1 3.55 13 ∞ 3.58

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.21872E+00, A4=−0.43653E−03, A6=0.16254E−02, A8=−0.19526E−02,        A10=0.12106E−02, A12=−0.25985E−03, A14=0.13192E−04        Third Surface    -   K=−0.30000E+02, A4=0.16876E−01, A6=−0.16928E−02, A8=0.14951E−03,        A10=−0.28576E−04, A12=−0.23762E−03, A14=−0.62790E−05        Fourth Surface    -   K=0.14738E+02, A4=−0.16775E−01, A6=0.13255E−01, A8=−0.80227E−02,        A10=0.28381E−02, A12=−0.13054E−02, A14=0.91730E−04        Fifth Surface    -   K=−0.36991E+01, A4=0.16472E−02, A6=0.20755E−01, A8=−0.80020E−02,        A10=0.49320E−02, A12=−0.20503E−02, A14=0.33114E−03        Sixth Surface    -   K=0.28805E+02, A4=−0.11426E−01, A6=−0.13054E−02, A8=0.52349E−02,        A10=−0.10253E−02, A12=−0.75642E−04, A14=0.13900E−03        Seventh Surface    -   K=0.30000E+02, A4=−0.95828E−02, A6=−0.10667E−02,        A8=−0.17348E−03, A10=−0.32525E−04, A12=−0.56450E−05,        A14=−0.69500E−06        Eighth Surface    -   K=0.30000E+02, A4=−0.31257E−02, A6=−0.98037E−03,        A8=−0.12892E−03, A10=−0.19314E−04, A12=−0.64080E−05,        A14=−0.28790E−05        Ninth Surface    -   K=−0.57350E+01, A4=−0.35001 E−01, A6=0.12792E−01,        A8=−0.26529E−02, A10=0.42193E−03, A12=−0.62270E−05,        A14=−0.31110E−05        Tenth Surface    -   K=0.49387E+00, A4=−0.42585E−01, A6=0.11271 E−01,        A8=−0.56345E−03, A10=−0.19862E−03, A12=0.38293E−04,        A14=−0.19550E−05        Eleventh Surface    -   K=−0.22116E+02, A4=−0.31591E−01, A6=0.59975E−02,        A8=−0.88137E−03, A10=0.81496E−04, A12=−0.47600E−05,        A14=0.11100E−06

Single lens data of the image pickup lens of Example 2 are listed below.

Lens Forefront surface Focal length (mm) 1 2 3.894 2 4 −7.056 3 6−88.872 4 8 4.664 5 10 −3.528

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 2 are listed below.f12/f=1.133  (1)f2/f=−1.232  (2)r4/f=0.475  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−1.772  (6)|f3|/f=15.518  (8)d456/f=0.298  (9)L/2Y=0.961  (10)

In Example 2, each of lenses is formed of a plastic material.

FIG. 6 shows a sectional view of the image pickup lens of Example 2. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 7 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 2.

Example 3

All the specifications of the image pickup lens of Example 3 are listedbelow.

-   f=5.61 mm-   fB=0.66 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.33 mm-   H1=−2.29 mm-   H2=−4.96 mm

Surface data of the image pickup lens of Example 3 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.38 1.36  2* 2.280 0.97 1.54470 56.2 1.42  3* 60.204 0.05 1.39  4*4.356 0.40 1.63200 23.4 1.39  5* 2.389 0.82 1.34  6* −8.520 0.39 1.6320023.4 1.44  7* −14.691 0.09 1.66  8* −23.903 1.75 1.54470 56.2 1.92  9*−1.695 0.44 2.46 10* −8.586 0.60 1.54470 56.2 2.73 11* 1.990 0.60 3.1612 ∞ 0.15 1.51630 64.1 3.38 13 ∞ 3.42

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.22694E+00, A4=0.18590E−04, A6=0.11569E−02, A8=−0.13986E−02,        A10=0.10509E−02, A12=−0.33663E−03, A14=0.47668E−04,        A16=0.13853E−04        Third Surface    -   K=0.30000E+02, A4=0.17132E−02, A6=0.43435E−02, A8=0.10139E−02,        A10=−0.10033E−03, A12=−0.40770E−03, A14=0.10269E−03,        A16=0.51383E−04        Fourth Surface    -   K=0.60221E+01, A4=−0.39201 E−01, A6=0.15832E−01, A8=−0.70161        E−02, A10=0.32874E−02, A12=−0.96583E−03, A14=−0.62578E−04        Fifth Surface    -   K=−0.32826E+01, A4=0.12941 E−03, A6=0.15212E−01,        A8=−0.76313E−02, A10=0.74565E−02, A12=−0.15810E−02,        A14=−0.15762E−03        Sixth Surface    -   K=0.32073E+02, A4=−0.40141E−01, A6=−0.46016E−02, A8=0.70656E−02,        A10=0.50951E−03, A12=0.52547E−03, A14=−0.96185E−04        Seventh Surface    -   K=0.10896E+02, A4=−0.34996E−01, A6=0.30209E−02, A8=0.79884E−03,        A10=0.78677E−03, A12=0.10670E−03, A14=−0.76501E−04        Eighth Surface    -   K=0.30000E+02, A4=0.47224E−02, A6=0.18239E−02, A8=−0.43199E−04,        A10=−0.12179E−03, A12=−0.68420E−05, A14=0.21960E−05        Ninth Surface    -   K=−0.50653E+01, A4=−0.32301 E−01, A6=0.15164E−01,        A8=−0.27777E−02, A10=0.32857E−03, A12=−0.14988E−04,        A14=−0.10960E−05        Tenth Surface    -   K=−0.66386E+01, A4=−0.40847E−01, A6=0.10072E−01,        A8=−0.47451E−03, A10=−0.19241E−03, A12=0.37777E−04,        A14=−0.21300E−05        Eleventh Surface    -   K=−0.90272E+01, A4=−0.30972E−01, A6=0.65030E−02,        A8=−0.96594E−03, A10=0.84387E−04, A12=−0.43170E−05,        A14=0.10600E−06

Single lens data of the image pickup lens of Example 3 are listed below.

Lens Forefront surface Focal length (mm) 1 2 4.325 2 4 −9.084 3 6−32.898 4 8 3.259 5 10 −2.908

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 3 are listed below.f12/f=1.158  (1)f2/f=−1.619  (2)r4/f=0.426  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−1.991  (6)|f3|/f=5.862  (8)d456/f=0.231  (9)L/2Y=0.961  (10)

In Example 3, each of lenses is formed of a plastic material.

FIG. 8 shows a sectional view of the image pickup lens of Example 3. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 9 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 3.

Example 4

All the specifications of the image pickup lens of Example 4 are listedbelow.

-   f=5.61 mm-   fB=0.36 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.38 mm-   H1=−2.80 mm-   H2=−5.25 mm

Surface data of the image pickup lens of Example 4 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.33 1.36  2* 2.554 1.03 1.54470 56.2 1.43  3* −29.139 0.06 1.40  4*4.187 0.40 1.63200 23.4 1.43  5* 2.024 0.80 1.45  6* −9.133 0.76 1.5447056.2 1.56  7* −3.158 0.51 1.78  8* −3.098 0.83 1.54470 56.2 2.24  9*−1.858 0.90 2.41 10* −14.682 0.50 1.54470 56.2 2.80 11* 2.213 0.60 3.2212 ∞ 0.15 1.51630 64.1 3.53 13 ∞ 3.57

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.29377E+00, A4=0.15368E−02, A6=0.24805E−02, A8=−0.17788E−02,        A10=0.11217E−02, A12=−0.24895E−03, A14=0.62224E−04        Third Surface    -   K=−0.30000E+02, A4=0.16680E−01, A6=−0.14116E−02, A8=0.17823E−02,        A10=0.45256E−04, A12=−0.32581E−03, A14=0.31983E−03        Fourth Surface    -   K=−0.25530E+01, A4=−0.36923E−01, A6=0.15093E−01,        A8=−0.76225E−02, A10=0.35689E−02, A12=−0.82534E−03,        A14=0.90528E−04        Fifth Surface    -   K=−0.35968E+01, A4=−0.79084E−02, A6=0.12894E−01,        A8=−0.82870E−02, A10=0.55697E−02, A12=−0.18973E−02,        A14=0.26203E−03        Sixth Surface    -   K=0.29911E+02, A4=−0.91254E−02, A6=−0.70032E−02, A8=0.38774E−02,        A10=−0.62823E−03, A12=0.13750E−03, A14=0.82812E−04        Seventh Surface    -   K=−0.82136E+01, A4=−0.21808E−01, A6=−0.99771 E−03,        A8=0.13069E−04, A10=0.70065E−04, A12=0.32811E−04,        A14=0.10138E−04        Eighth Surface    -   K=−0.10688E+02, A4=0.23875E−02, A6=0.78342E−03, A8=0.20442E−03,        A10=0.15400E−04, A12=−0.23940E−05, A14=−0.11160E−05        Ninth Surface    -   K=−0.53403E+01, A4=−0.29088E−01, A6=0.13318E−01,        A8=−0.27984E−02, A10=0.39290E−03, A12=−0.76800E−05,        A14=−0.23880E−05        Tenth Surface    -   K=0.11262E+02, A4=−0.52401E−01, A6=0.10923E−01, A8=−0.55106E−03,        A10=−0.19886E−03, A12=0.38280E−04, A14=−0.19510E−05        Eleventh Surface    -   K=−0.97709E+01, A4=−0.31957E−01, A6=0.61905E−02,        A8=−0.91975E−03, A10=0.81571E−04, A12=−0.45010E−05,        A14=0.12400E−06

Single lens data of the image pickup lens of Example 4 are listed below.

Lens Forefront surface Focal length (mm) 1 2 4.361 2 4 −6.680 3 6 8.4794 8 6.891 5 10 −3.495

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 4 are listed below.f12/f=1.477  (1)f2/f=−1.190  (2)r4/f=0.361  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−2.171  (6)|f3|/f=1.510  (8)d456/f=0.370  (9)L/2Y=0.960  (10)

In Example 4, each of lenses is formed of a plastic material.

FIG. 10 shows a sectional view of the image pickup lens of Example 4. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 11 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 4.

Example 5

All the specifications of the image pickup lens of Example 5 are listedbelow.

-   f=5.77 mm-   fB=0.23 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.41 mm-   H1=−3.38 mm-   H2=−5.54 mm

Surface data of the image pickup lens of Example 5 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.43 1.40  2* 2.329 0.99 1.49700 81.0 1.40  3* 37.946 0.20 1.39  4*3.101 0.40 1.63200 23.4 1.43  5* 2.061 0.87 1.41  6* −9.283 0.50 1.5447056.2 1.58  7* 21.886 0.23 1.86  8* 6.108 1.43 1.54470 56.2 2.26  9*−2.523 0.80 2.53 10* −2.857 0.50 1.54470 56.2 2.79 11* 5.044 0.60 3.2212 ∞ 0.15 1.51630 64.1 3.60 13 ∞ 3.64

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.20251E+00, A4=−0.79646E−03, A6=0.18757E−02, A8=−0.17493E−02,        A10=0.12709E−02, A12=−0.31631E−03, A14=0.91500E−05,        A16=0.16924E−04        Third Surface    -   K=0.30000E+02, A4=−0.50808E−02, A6=0.11253E−01, A8=−0.38116E−02,        A10=0.94986E−03, A12=0.30224E−04, A14=−0.12530E−03,        A16=0.64213E−04        Fourth Surface    -   K=0.16136E+01, A4=−0.49199E−01, A6=0.19614E−01, A8=−0.87208E−02,        A10=0.23983E−02, A12=−0.62276E−03, A14=0.25973E−04        Fifth Surface    -   K=−0.30823E+01, A4=0.71074E−03, A6=0.13793E−01, A8=−0.72002E−02,        A10=0.63443E−02, A12=−0.26787E−02, A14=0.42393E−03,        Sixth Surface    -   K=0.30000E+02, A4=−0.43396E−01, A6=0.23275E−02, A8=0.26839E−02,        A10=0.86392E−03, A12=0.69765E−03, A14=−0.24180E−03        Seventh Surface    -   K=−0.30000E+02, A4=−0.74959E−01, A6=0.10109E−01,        A8=−0.26199E−03, A10=0.73873E−03, A12=0.21845E−03,        A14=−0.85434E−04        Eighth Surface    -   K=−0.18613E+01, A4=−0.33465E−01, A6=0.85736E−04, A8=0.14325E−02,        A10=−0.70444E−04, A12=−0.28393E−04, A14=0.23740E−05        Ninth Surface    -   K=−0.70987E+01, A4=−0.27789E−01, A6=0.89909E−02,        A8=−0.25339E−02, A10=0.37953E−03, A12=−0.12827E−04,        A14=−0.99000E−06        Tenth Surface    -   K=−0.18307E+01, A4=−0.36272E−01, A6=0.90771E−02,        A8=−0.43830E−03, A10=−0.19921E−03, A12=0.37408E−04,        A14=−0.18940E−05        Eleventh Surface    -   K=−0.30000E+02, A4=−0.30376E−01, A6=0.54714E−02,        A8=−0.85228E−03, A10=0.85435E−04, A12=−0.55890E−05,        A14=0.17600E−06

Single lens data of the image pickup lens of Example 5 are listed below.

Lens Forefront surface Focal length (mm) 1 2 4.947 2 4 −11.426 3 6−11.900 4 8 3.482 5 10 −3.276

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 5 are listed below.f12/f=1.190  (1)f2/f=−1.981  (2)r4/f=0.357  (3)v1−v2=57.6  (4)n2=1.632  (5)Pair23/P=−2.198  (6)|f3|/f=2.063  (8)d456/f=0.278  (9)L/2Y=0.960  (10)

In Example 5, the first lens is formed of a molded glass lens, and eachof the second through fifth lenses is formed of a plastic material.

FIG. 12 shows a sectional view of the image pickup lens of Example 5. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 13 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 5.

Example 6

All the specifications of the image pickup lens of Example 6 are listedbelow.

-   f=4.93 mm-   fB=1.00 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.78 mm-   H1=−0.15 mm-   H2=−3.92 mm

Surface data of the image pickup lens of Example 6 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.23 1.19  2* 2.665 0.85 1.54470 56.2 1.20  3* −58.565 0.05 1.28  4*5.418 0.40 1.63200 23.4 1.31  5* 3.021 0.66 1.37  6* 34.726 0.50 1.6320023.4 1.35  7* 7.516 0.11 1.74  8* −8.533 1.71 1.54470 56.2 1.99  9*−1.181 0.22 2.17 10* 8.922 0.66 1.54470 56.2 2.71 11* 1.215 0.60 3.26 12∞ 0.15 1.51630 64.1 3.48 13 ∞ 3.50

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.19361E+00, A4=−0.12007E−03, A6=0.10971E−02, A8=−0.21027E−02,        A10=0.10782E−02, A12=−0.32493E−03, A14=−0.18897E−04,        A16=−0.17190E−04        Third Surface    -   K=0.19270E+02, A4=0.69555E−02, A6=0.15205E−02, A8=−0.39410E−02,        A10=−0.11630E−02, A12=−0.38025E−03, A14=0.45100E−03,        A16=−0.15763E−04        Fourth Surface    -   K=0.80889E+01, A4=−0.31840E−01, A6=0.15405E−01, A8=−0.11624E−01,        A10=0.10647E−02, A12=−0.11480E−02, A14=0.60122E−03        Fifth Surface    -   K=−0.79886E+01, A4=−0.15359E−01, A6=0.71172E−02,        A8=−0.12256E−01, A10=0.43282E−02, A12=−0.25095E−02,        A14=0.35186E−03        Sixth Surface    -   K=−0.30000E+02, A4=−0.86169E−01, A6=−0.13295E−01,        A8=−0.26623E−02, A10=−0.25559E−02, A12=0.51722E−03,        A14=0.10940E−03        Seventh Surface    -   K=−0.30000E+02, A4=−0.39031E−01, A6=0.82630E−03, A8=0.27459E−03,        A10=0.46098E−03, A12=0.70396E−04, A14=−0.19480E−04        Eighth Surface    -   K=−0.29314E+02, A4=0.38879E−02, A6=0.34032E−02, A8=0.13683E−03,        A10=−0.13016E−03, A12=−0.12700E−04, A14=0.48110E−05        Ninth Surface    -   K=−0.33988E+01, A4=−0.50420E−01, A6=0.12125E−01,        A8=−0.24328E−02, A10=0.43971E−03, A12=−0.91800E−05,        A14=−0.14760E−05        Tenth Surface    -   K=−0.50566E+01, A4=−0.54533E−01, A6=0.93922E−02,        A8=−0.49089E−03, A10=−0.19221E−03, A12=0.37826E−04,        A14=−0.19210E−05        Eleventh Surface    -   K=−0.54672E+01, A4=−0.33453E−01, A6=0.64837E−02,        A8=−0.10105E−02, A10=0.90814E−04, A12=−0.45890E−05,        A14=0.10000E−06

Single lens data of the image pickup lens of Example 6 are listed below.

Lens Forefront surface Focal length (mm) 1 2 4.703 2 4 −11.553 3 6−15.287 4 8 2.326 5 10 −2.662

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 6 are listed below.f12/f=1.375  (1)f2/f=−2.345  (2)r4/f=0.613  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−0.929  (6)|f3|/f=3.103  (8)d456/f=0.258  (9)L/2Y=0.961  (10)

In Example 6, each of lenses is formed of a plastic material.

FIG. 14 shows a sectional view of the image pickup lens of Example 6. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 15 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 6.

Example 7

All the specifications of the image pickup lens of Example 7 are listedbelow.

-   f=5.68 mm-   fB=0.81 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.83 mm-   EXTP=−3.43 mm-   H1=−1.11 mm-   H2=−4.88 mm

Surface data of the image pickup lens of Example 7 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1* 2.342 1.061.54470 56.2 1.56  2* −58.079 0.01 1.22  3(Stop) ∞ 0.07 1.22  4* 4.6770.39 1.63200 23.4 1.24  5* 2.229 0.82 1.26  6* −7.860 0.40 1.63200 23.41.33  7* −9.548 0.05 1.64  8* −8.402 1.85 1.54470 56.2 2.03  9* −1.5290.47 2.44 10* −16.141 0.56 1.54470 56.2 2.71 11* 1.875 0.60 3.24 12 ∞0.15 1.51630 64.1 3.56 13 ∞ 0.81 3.58

Aspheric surface coefficients are listed below.

First Surface

-   -   K=0.23047E+00, A4=0.89763E−04, A6=0.17308E−02, A8=−0.16946E−02,        A10=0.10607E−02, A12=−0.31325E−03, A14=0.49546E−04,        A16=−0.23560E−05        Second Surface    -   K=−0.29994E+02, A4=0.98771 E−02, A6=0.11567E−02,        A8=−0.91467E−03, A10=0.21042E−03, A12=−0.13949E−03,        A14=0.57385E−04, A16=−0.20970E−05        Fourth Surface    -   K=0.62552E+01, A4=−0.40944E−01, A6=0.16012E−01, A8=−0.90175E−02,        A10=0.25719E−02, A12=−0.30065E−03, A14=−0.64825E−04        Fifth Surface    -   K=−0.40017E+01, A4=−0.22330E−02, A6=0.12835E−01,        A8=−0.94790E−02, A10=0.52031E−02, A12=−0.11520E−02,        A14=0.11035E−04        Sixth Surface    -   K=0.32000E+02, A4=−0.51804E−01, A6=−0.11134E−01, A8=0.26388E−02,        A10=−0.15859E−02, A12=0.41871E−03, A14=0.56801E−03        Seventh Surface    -   K=0.23502E+02, A4=−0.27913E−01, A6=−0.18212E−02, A8=−0.46301        E−03, A10=0.80285E−03, A12=0.20144E−03, A14=−0.36715E−04        Eighth Surface    -   K=−0.13644E+02, A4=0.10267E−01, A6=0.16826E−02, A8=−0.10129E−03,        A10=−0.78692E−04, A12=0.57750E−05, A14=−0.10490E−05        Ninth Surface    -   K=−0.40404E+01, A4=−0.39458E−01, A6=0.13630E−01,        A8=−0.26403E−02, A10=0.35834E−03, A12=−0.14324E−04,        A14=−0.17910E−05        Tenth Surface    -   K=−0.24851E+02, A4=−0.42443E−01, A6=0.95223E−02,        A8=−0.53673E−03, A10=−0.19538E−03, A12=0.37876E−04,        A14=−0.20480E−05        Eleventh Surface    -   K=−0.80235E+01, A4=−0.31123E−01, A6=0.64172E−02,        A8=−0.97433E−03, A10=0.83458E−04, A12=−0.43540E−05,        A14=0.11500E−06

Single lens data of the image pickup lens of Example 7 are listed below.

Lens Forefront surface Focal length (mm) 1 1 4.159 2 4 −7.178 3 6−77.440 4 8 3.134 5 10 −3.050

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 7 are listed below.f12/f=1.237  (1)f2/f=−1.263  (2)r4/f=0.392  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−2.175  (6)|f3|/f=13.625  (8)d456/f=0.223  (9)L/2Y=1.005  (10)

In Example 7, each of lenses is formed of a plastic material.

FIG. 16 shows a sectional view of the image pickup lens of Example 7. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 17 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 7.

Example 8

All the specifications of the image pickup lens of Example 8 are listedbelow.

-   f=5.61 mm-   fB=0.70 mm-   F=2.06-   2Y=7.140 mm-   ENTP=0.00 mm-   EXTP=−3.60 mm-   H1=−1.69 mm-   H2=−4.90 mm

Surface data of the image pickup lens of Example 8 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.30 1.36  2* 2.626 0.91 1.69350 53.2 1.38  3* 31.430 0.10 1.40  4*5.860 0.40 1.63200 23.4 1.39  5* 2.534 0.78 1.36  6* −8.265 0.50 1.6320023.4 1.50  7* −12.646 0.35 1.68  8* −49.423 1.46 1.54470 56.2 2.18  9*−1.777 0.45 2.45 10* −9.688 0.50 1.54470 56.2 2.67 11* 2.176 0.60 3.1112 ∞ 0.15 1.51630 64.1 3.38 13 ∞ 3.40

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.15508E+00, A4=−0.87045E−03, A6=0.69963E−03, A8=−0.16953E−02,        A10=0.97778E−03, A12=−0.33620E−03, A14=0.36419E−04,        A16=−0.61097E−05        Third Surface    -   K=0.24933E+02, A4=−0.23260E−02, A6=0.17948E−02, A8=−0.28039E−03,        A10=−0.38440E−03, A12=−0.36371E−03, A14=0.15315E−03,        A16=−0.23132E−04        Fourth Surface    -   K=0.86801E+01, A4=−0.28104E−01, A6=0.17251E−01, A8=−0.76766E−02,        A10=0.27746E−02, A12=−0.11333E−02, A14=0.76469E−04        Fifth Surface    -   K=−0.36516E+01, A4=0.59919E−02, A6=0.18297E−01, A8=−0.87590E−02,        A10=0.67621E−02, A12=−0.14959E−02, A14=−0.18450E−03        Sixth Surface    -   K=0.24844E+02, A4=−0.32566E−01, A6=0.26232E−03, A8=0.57545E−02,        A10=0.53935E−03, A12=0.73479E−03, A14=−0.29141E−03        Seventh Surface    -   K=0.18273E+02, A4=−0.29240E−01, A6=0.49183E−02, A8=0.91335E−03,        A10=0.58095E−03, A12=0.80029E−04, A14=−0.55161E−04        Eighth Surface    -   K=0.25000E+02, A4=−0.13819E−02, A6=0.13979E−02, A8=0.18682E−03,        A10=−0.60174E−04, A12=−0.90736E−06, A14=0.45223E−06        Ninth Surface    -   K=−0.56352E+01, A4=−0.31650E−01, A6=0.13922E−01,        A8=−0.28640E−02, A10=0.32907E−03, A12=−0.13209E−04,        A14=−0.45117E−06        Tenth Surface    -   K=0.53311E+01, A4=−0.41119E−01, A6=0.96922E−02, A8=−0.53135E−03,        A10=−0.19677E−03, A12=0.37983E−04, A14=−0.19656E−05        Eleventh Surface    -   K=−0.11151E+02, A4=−0.32603E−01, A6=0.62546E−02,        A8=−0.93502E−03, A10=0.83336E−04, A12=−0.45432E−05,        A14=0.11774E−06

Single lens data of the image pickup lens of Example 8 are listed below.

Lens Forefront surface Focal length (mm) 1 2 4.079 2 4 −7.408 3 6−39.498 4 8 3.348 5 10 −3.214

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 8 are listed below.f12/f=1.209  (1)f2/f=−1.322  (2)r4/f=0.452  (3)v1−v2=29.8  (4)n2=1.632  (5)Pair23/P=−1.910  (6)|f3|/f=7.047  (8)d456/f=0.291  (9)L/2Y=0.960  (10)

In Example 8, the first lens is formed of a molded glass lens, and eachof the second through fifth lenses is formed of a plastic material.

FIG. 18 shows a sectional view of the image pickup lens of Example 8. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 19 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 8.

Example 9

All the specifications of the image pickup lens of Example 9 are listedbelow.

-   f=3.61 mm-   fB=0.39 mm-   F=2.06-   2Y=4.48 mm-   ENTP=0.00 mm-   EXTP=−2.30 mm-   H1=−1.24 mm-   H2=−3.22 mm

Surface data of the image pickup lens of Example 9 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.14 0.88  2* 1.852 0.66 1.54470 56.2 0.89  3* −12.167 0.12 0.94  4*3.704 0.35 1.63200 23.4 0.98  5* 1.569 0.40 0.97  6* 4.865 0.35 1.6320023.4 1.05  7* 5.427 0.23 1.18  8* −96.022 1.14 1.54470 56.2 1.34  9*−0.884 0.13 1.53 10* −18.193 0.40 1.54470 56.2 1.68 11* 0.826 0.40 2.0212 ∞ 0.15 1.51630 64.1 2.10 13 ∞ 2.12

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.10631 E−01, A4=−0.10057E−01, A6=0.11933E−01,        A8=−0.50449E−01, A10=0.71656E−01, A12=−0.58082E−01,        A14=0.17190E−01        Third Surface    -   K=0.30000E+02, A4=−0.18368E−01, A6=0.81203E−01, A8=−0.99672E−01,        A10=0.11165E−01, A12=0.54838E−01, A14=−0.31170E−01        Fourth Surface    -   K=0.81380E+01, A4=−0.14141E+00, A6=0.22888E+00, A8=−0.26223E+00,        A10=0.14821E+00, A12=−0.38855E−01, A14=0.59288E−02        Fifth Surface    -   K=−0.49618E+01, A4=−0.16074E−01, A6=0.17837E+00,        A8=−0.25983E+00, A10=0.33521E+00, A12=−0.29218E+00,        A14=0.11473E+00        Sixth Surface    -   K=0.98544E+00, A4=−0.12169E+00, A6=0.43174E−02, A8=0.51214E−01,        A10=−0.23021E−02, A12=0.13907E−01, A14=−0.20352E−01        Seventh Surface    -   K=0.12055E+02, A4=−0.76270E−01, A6=0.21440E−01, A8=−0.88727E−01,        A10=0.13836E+00, A12=−0.58141E−01, A14=0.46039E−02        Eighth Surface    -   K=0.30000E+02, A4=0.31981 E−01, A6=−0.12836E−01,        A8=−0.22187E−01, A10=0.66583E−02, A12=0.66984E−02,        A14=−0.21987E−02        Ninth Surface    -   K=−0.49531E+01, A4=0.10167E+00, A6=0.10512E+00, A8=−0.56999E−01,        A10=0.17059E−01, A12=−0.51067E−02, A14=0.10718E−02        Tenth Surface    -   K=−0.20682E+02, A4=−0.17526E+00, A6=0.94906E−01,        A8=−0.12382E−01, A10=−0.12609E−01, A12=0.60013E−02,        A14=−0.76036E−03        Eleventh Surface    -   K=−0.62341E+01, A4=−0.11891E+00, A6=0.62455E−01,        A8=−0.23532E−01, A10=0.54495E−02, A12=−0.72881E−03,        A14=0.43268E−04

Single lens data of the image pickup lens of Example 9 are listed below.

Lens Forefront surface Focal length (mm) 1 2 3.000 2 4 −4.601 3 6 59.9254 8 1.631 5 10 −1.440

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 9 are listed below.f12/f=1.534  (1)f2/f=−1.276  (2)r4/f=0.435  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−0.909  (6)|f3|/f=16.613  (8)d456/f=0.271  (9)L/2Y=1.040  (10)

In Example 9, the first lens is formed of a molded glass lens, and eachof the second through fifth lenses is formed of a plastic material.

FIG. 20 shows a sectional view of the image pickup lens of Example 9. Inthe figure, L1 represents the first lens, L2 represents the second lens,L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 21 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 9.

Example 10

All the specifications of the image pickup lens of Example 10 are listedbelow.

-   f=3.62 mm-   fB=0.62 mm-   F=2.06-   2Y=4.50 mm-   ENTP=0.00 mm-   EXTP=−1.95 mm-   H1=−1.49 mm-   H2=−3.01 mm

Surface data of the image pickup lens of Example 10 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞−0.30 0.88  2* 1.511 0.70 1.54470 56.2 0.88  3* −10.723 0.05 0.90  4*4.941 0.35 1.63200 23.4 0.90  5* 1.535 0.41 0.90  6* −7.026 0.35 1.5830030.0 1.00  7* −14.330 0.05 1.10  8* −49.611 1.03 1.54470 56.2 1.20  9*−1.003 0.27 1.50 10* −3.260 0.40 1.54470 56.2 1.70 11* 1.387 0.16 2.0012 ∞ 0.15 1.51680 64.2 2.40 13 ∞ 2.40

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.26408E+00, A4=0.29716E−02, A6=0.14665E−01, A8=−0.35400E−01,        A10=0.74560E−01, A12=−0.49028E−01, A14=0.18846E−01        Third Surface    -   K=−0.30000E+02, A4=0.57582E−01, A6=0.55984E−02, A8=0.29750E−01,        A10=−0.87303E−02, A12=−0.66251E−01, A14=0.31630E−01        Fourth Surface    -   K=0.10000E+02, A4=−0.10739E+00, A6=0.15115E+00, A8=−0.20859E+00,        A10=0.17872E+00, A12=−0.17956E+00, A14=0.10637E−01        Fifth Surface    -   K=−0.43515E+01, A4=−0.14707E−01, A6=0.17275E+00,        A8=−0.20691E+00, A10=0.34057E+00, A12=−0.31457E+00,        A14=0.10537E+00        Sixth Surface    -   K=0.29405E+02, A4=−0.12377E+00, A6=−0.13716E−01, A8=0.15016E+00,        A10=0.62940E−01, A12=0.65542E−01, A14=−0.12521E+00        Seventh Surface    -   K=0.30000E+02, A4=−0.89231E−01, A6=−0.49504E−02, A8=0.52767E−01,        A10=0.35405E−01, A12=−0.80319E−03, A14=−0.17326E−01        Eighth Surface    -   K=−0.20000E+02, A4=−0.65194E−02, A6=0.63353E−02, A8=0.11005E−01,        A10=0.17189E−02, A12=−0.14236E−02, A14=−0.22780E−02        Ninth Surface    -   K=−0.44340E+01, A4=−0.14296E+00, A6=0.15642E+00,        A8=−0.72174E−01, A10=0.22527E−01, A12=−0.19585E−02,        A14=−0.81916E−03        Tenth Surface    -   K=0.78130E+00, A4=−0.12832E+00, A6=0.11001E+00, A8=−0.14964E−01,        A10=−0.12910E−01, A12=0.60002E−02, A14=−0.77936E−03        Eleventh Surface    -   K=−0.11461E+02, A4=−0.13068E+00, A6=0.70515E−01,        A8=−0.24317E−01, A10=0.51457E−02, A12=−0.72477E−03,        A14=0.52668E−04

Single lens data of the image pickup lens of Example 10 are listedbelow.

Lens Forefront surface Focal length (mm) 1 2 2.482 2 4 −3.671 3 6−24.067 4 8 1.866 5 10 −1.734

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 10 are listed below.f12/f=1.277  (1)f2/f=−1.013  (2)r4/f=0.424  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−1.843  (6)|f3|/f=6.640  (8)d456/f=0.223  (9)L/2Y=1.001  (10)

In Example 10, the first lens is formed of a molded glass lens, and eachof the second through fifth lenses is formed of a plastic material.

FIG. 22 shows a sectional view of the image pickup lens of Example 10.In the figure, L1 represents the first lens, L2 represents the secondlens, L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 23 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 10.

Example 11

All the specifications of the image pickup lens of Example 11 are listedbelow.

-   f=4.60 mm-   fB=0.40 mm-   F=2.88-   2Y=7.14 mm-   ENTP=0.00 mm-   EXTP=−3.07 mm-   H1=−1.50 mm-   H2=−4.20 mm

Surface data of the image pickup lens of Example 11 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1(Stop) ∞ 0.00 0.80  2* 2.445 0.78 1.54470 56.2 0.92  3* −11.409 0.07 1.04  4* 6.1840.35 1.63200 23.4 1.10  5* 2.064 0.44 1.19  6* 16.514 0.58 1.54470 56.21.38  7* −40.318 0.33 1.54  8* −22.031 1.09 1.54470 56.2 1.91  9* −1.7380.73 2.08 10* −16.209 0.50 1.54470 56.2 2.47 11* 1.750 0.60 3.09 12 ∞0.15 1.51630 64.1 3.34 13 ∞ 3.39

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.34852E+00, A4=0.95169E−03, A6=0.45053E−03, A8=−0.14078E−02,        A10=0.11006E−02, A12=0.25515E−03, A14=0.17386E−02        Third Surface    -   K=−0.30000E+02, A4=0.27328E−01, A6=0.11966E−02, A8=0.29100E−02,        A10=0.21339E−02, A12=0.42425E−03, A14=−0.45296E−03        Fourth Surface    -   K=0.39989E+01, A4=−0.43443E−01, A6=0.25867E−01, A8=−0.38316E−02,        A10=0.36971E−02, A12=−0.16886E−02, A14=−0.76694E−03        Fifth Surface    -   K=−0.53885E+01, A4=−0.29279E−02, A6=0.18318E−01,        A8=−0.83248E−02, A10=0.56376E−02, A12=−0.20547E−02,        A14=0.39571E−04        Sixth Surface    -   K=0.30000E+02, A4=−0.26312E−01, A6=0.20648E−02, A8=0.51607E−02,        A10=0.67073E−03, A12=0.22844E−03, A14=−0.23941E−03        Seventh Surface    -   K=0.30000E+02, A4=−0.26519E−01, A6=−0.77065E−03, A8=0.19234E−02,        A10=0.86691E−03, A12=0.13548E−03, A14=−0.67858E−04        Eighth Surface    -   K=−0.29838E+02, A4=0.78863E−03, A6=0.14268E−02, A8=0.66303E−03,        A10=−0.30077E−04, A12=−0.18786E−04, A14=−0.11717E−05        Ninth Surface    -   K=−0.46460E+01, A4=−0.29285E−01, A6=0.16408E−01,        A8=−0.27466E−02, A10=0.34675E−03, A12=−0.14412E−04,        A14=−0.25625E−05        Tenth Surface    -   K=0.16766E+02, A4=−0.48178E−01, A6=0.95145E−02, A8=−0.47897E−03,        A10=−0.17233E−03, A12=0.39375E−04, A14=−0.23703E−05        Eleventh Surface    -   K=−0.62315E+01, A4=−0.29266E−01, A6=0.59213E−02,        A8=−0.91132E−03, A10=0.85007E−04, A12=−0.47477E−05,        A14=0.12725E−06

Single lens data of the image pickup lens of Example 11 are listedbelow.

Lens Forefront surface Focal length (mm) 1 2 3.772 2 4 −5.070 3 6 21.5864 8 3.401 5 10 −2.871

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 11 are listed below.f12/f=1.950  (1)f2/f=−1.101  (2)r4/f=0.448  (3)v1−v2=32.6  (4)n2=1.632  (5)Pair23/P=−1.238  (8)|f3|/f=4.688  (9)L/2Y=0.293  (10)

In Example 11, the first lens is formed of a molded glass lens, and eachof the second through fifth lenses is formed of a plastic material.

FIG. 24 shows a sectional view of the image pickup lens of Example 11.In the figure, L1 represents the first lens, L2 represents the secondlens, L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 25 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 11.

Example 12

All the specifications of the image pickup lens of Example 12 are listedbelow.

-   f=5.03 mm-   fB=0.37 mm-   F=2.88-   2Y=7.016 mm-   ENTP=0.64 mm-   EXTP=−3.04 mm-   H1=−1.77 mm-   H2=−4.66 mm

Surface data of the image pickup lens of Example 12 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1 ∞ 0.00 1.39 2* 2.076 0.74 1.62260 58.2 1.14  3* 9.861 0.08 0.84  4 (Stop) ∞ 0.070.76  5* 3.580 0.32 2.00170 19.3 0.80  6* 2.302 0.49 0.84  7* −4.9770.68 1.54470 56.2 1.07  8* −2.512 0.76 1.33  9* −2.866 0.87 1.54470 56.21.74 10* −1.150 0.32 2.04 11* −2.863 0.45 1.54470 56.2 2.61 12 2.0520.60 3.04 13 ∞ 0.30 1.51630 64.1 3.44 14 ∞ 3.51

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.17081E+00, A4=0.57736E−03, A6=0.11941 E−02, A8=−0.21949E−03,        A10=−0.40061 E−03, A12=0.13228E−02, A14=−0.64952E−03        Third Surface    -   K=−0.30000E+02, A4=−0.19978E−01, A6=0.35103E−01,        A8=−0.29652E−01, A10=0.15784E−01, A12=−0.14700E−02,        A14=−0.42152E−02        Fifth Surface    -   K=−0.10189E+02, A4=−0.21921E−01, A6=0.44111E−01,        A8=−0.49675E−01, A10=0.41320E−01, A12=−0.14420E−01,        A14=−0.70668E−02        Sixth Surface    -   K=−0.29336E+01, A4=0.68393E−03, A6=0.39910E−01, A8=−0.20513E−01,        A10=0.11484E−01, A12=0.80308E−02, A14=−0.12193E−01        Seventh Surface    -   K=0.16240E+02, A4=−0.24158E−01, A6=0.90376E−02, A8=0.29408E−02,        A10=0.93887E−02, A12=0.39989E−02, A14=0.25658E−02        Eighth Surface    -   K=0.83881E+00, A4=−0.19966E−01, A6=0.83970E−02, A8=−0.56282E−02,        A10=0.25793E−02, A12=−0.55828E−05, A14=0.46892E−03        Ninth Surface    -   K=0.64207E−01, A4=−0.40683E−01, A6=0.23565E−01, A8=−0.48901        E−02, A10=−0.44936E−03, A12=0.55284E−03, A14=−0.84814E−04        Tenth Surface    -   K=−0.32016E+01, A4=−0.49758E−01, A6=0.14552E−01,        A8=−0.14208E−02, A10=0.25295E−03, A12=−0.28664E−04,        A14=−0.10014E−05

Single lens data of the image pickup lens of Example 12 are listedbelow.

Lens Forefront surface Focal length (mm) 1 2 4.074 2 4 −7.369 3 6 8.4894 8 2.992 5 10 −2.126

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 12 are listed below.f12/f=1.32  (1)f2/f=−1.47  (2)r4/f=0.46  (3)v1−v2=38.6  (4)n2=2.002  (5)Pair23/P=−2.86  (6)|f3|/f=1.69  (8)d456/f=0.38  (9)L/2Y=0.85  (10)

In Example 12, each of the first lens and the second lens is formed of amolded glass lens, and each of the third through fifth lenses is formedof a plastic material.

FIG. 26 shows a sectional view of the image pickup lens of Example 12.In the figure, L1 represents the first lens, L2 represents the secondlens, L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 27 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 12.

Example 13

All the specifications of the image pickup lens of Example 13 are listedbelow.

-   f=5.07 mm-   fB=0.3 mm-   F=2.79-   2Y=7.016 mm-   ENTP=0.66 mm-   EXTP=−3.09 mm-   H1=−1.87 mm-   H2=−4.78 mm

Surface data of the image pickup lens of Example 13 are listed below.

Surface number r (mm) d (mm) Nd vd Effective radius (mm)  1 ∞ 0.00 1.45 2* 1.990 0.78 1.58910 61.3 1.17  3* 22.611 0.06 0.87  4(Stop) ∞ 0.070.79  5* 3.996 0.30 1.84670 23.8 0.82  6* 2.114 0.52 0.87  7* −5.3280.75 1.54470 56.2 1.14  8* −2.477 0.73 1.40  9* −2.458 0.74 1.54470 56.21.80 10* −1.318 0.45 2.10 11* −3.805 0.47 1.54470 56.2 2.72 12 2.4320.60 3.12 13 ∞ 0.30 1.51630 64.1 3.51 14 ∞ 3.59

Aspheric surface coefficients are listed below.

Second Surface

-   -   K=0.16048E+00, A4=0.44085E−03, A6=0.16448E−02, A8=−0.13931E−02,        A10=−0.66799E−03, A12=0.27957E−02, A14=−0.16437E−02        Third Surface    -   K=−0.30000E+02, A4=−0.15140E−01, A6=0.38292E−01,        A8=−0.40451E−01, A10=0.21525E−01, A12=−0.49219E−02,        A14=−0.38410E−02        Fifth Surface    -   K=−0.15084E+02, A4=−0.27916E−01, A6=0.58588E−01,        A8=−0.66309E−01, A10=0.51360E−01, A12=−0.28248E−01,        A14=−0.12346E−02        Sixth Surface    -   K=−0.30864E+01, A4=0.55676E−03, A6=0.54032E−01, A8=−0.26718E−01,        A10=0.91528E−02, A12=0.89625E−02, A14=−0.12265E−01        Seventh Surface    -   K=0.18880E+02, A4=−0.28541 E−01, A6=0.10280E−01,        A8=−0.82048E−04, A10=0.81285E−02, A12=0.37207E−02,        A14=0.30301E−02        Eighth Surface    -   K=0.91085E+00, A4=−0.23223E−01, A6=0.10704E−01, A8=−0.78952E−02,        A10=0.32298E−02, A12=−0.41123E−03, A14=0.40575E−03        Ninth Surface    -   K=−0.10664E+00, A4=−0.46339E−01, A6=0.31462E−01,        A8=−0.63701E−02, A10=−0.67015E−03, A12=0.84181E−03,        A14=−0.14368E−03        Tenth Surface    -   K=−0.28588E+01, A4=−0.52964E−01, A6=0.18411E−01,        A8=−0.19022E−02, A10=0.33631E−03, A12=−0.48093E−04,        A14=−0.17968E−05

Single lens data of the image pickup lens of Example 13 are listedbelow.

Lens Forefront surface Focal length (mm) 1 2 3.652 2 4 −5.723 3 6 7.7794 8 4.248 5 10 −2.654

Values corresponding to the conditional expressions (1) to (6), and (8)to (10) of the image pickup lens of Example 13 are listed below.f12/f=1.33  (1)f2/f=−1.13  (2)r4/f=0.42  (3)v1−v2=37.5  (4)n2=1.847  (5)Pair23/P=−2.66  (6)|f3|/f=1.53  (8)d456/f=0.39  (9)L/2Y=0.85  (10)

In Example 13, each of the first and second lenses is formed of a moldedglass lens, and each of the third through fifth lenses is formed of aplastic material.

FIG. 28 shows a sectional view of the image pickup lens of Example 13.In the figure, L1 represents the first lens, L2 represents the secondlens, L3 represents the third lens, L4 represents the fourth lens, L5represents the fifth lens, S represents an aperture stop, and Irepresents an image pickup plane. Further, F represents a parallel flatplate provided on the assumption such as an optical low-pass filter, aninfrared blocking filter, and a sealing glass of a solid-state imagepickup element. FIG. 29 shows aberration diagrams (spherical aberration,astigmatism, distortion, and meridional coma) of the image pickup lensof Example 13.

In plastic materials, refractive-index change caused when temperaturechanges is large. Therefore, when each of the first through fifth lensesis formed of a plastic material, it causes a problem that a position ofthe image point of the total system of the image pickup lens fluctuatesunder the condition that the ambient temperature changes.

In recent years, it has been known that the change in a plastic materialdue to temperature can be made small by blending inorganicmicroparticles in a plastic material. The detailed explanation isdescribed below. When microparticles are blended in a transparentplastic material, the plastic materials have been hardly used as opticalmaterials because transmittance of the transparent plastic materials waslowered due to scattering of light, as generally known. However, it ispossible not to cause the scattering substantially by reducing the sizeof microparticles to be smaller than a wavelength of a transmittinglight flux. A plastic material has a refractive index decreasing whenits temperature rises, while, inorganic particles have a refractiveindex increasing when its temperature rises. It is therefore possiblethat a change in refractive index hardly occurs by employing a plasticmaterial and inorganic particles whose temperature dependencies work tocancel each other. Specifically, by dispersing inorganic particles whoselargest side is 20 nm or less into a plastic material representing abase material, it is possible to realize a plastic material having arefractive index whose temperature dependency is extremely low. Forexample, by dispersing microparticles of niobium oxide (Nb₂O₅) intoacrylic resin, the material can provide reduced change in the refractiveindex caused by temperature changes. In the above examples, by employingplastic materials in which the aforesaid inorganic particles aredispersed, for positive lens (L1) whose refractive power is relativelylarge or for all lenses (L1-L5), the fluctuation of the image pointposition caused by temperature changes in the total system of imagepickup lens can be controlled to be small.

Incidentally, each of the above examples is not necessarily designedsuch that an incident angle of a principal ray of the light flux thatenters an image pickup surface of a solid-state image pickup element issufficiently small at a peripheral portion of the image pickup surface.However, in the recent technology, it has become possible to reduceshading by a revision of an arrangement of a color filter of asolid-state image pickup element and an onchip-microlens-array.Specifically, if a pitch of the arrangement of the color filter and theonchip-microlens-array is designed to be slightly smaller compared witha pixel pitch of the image pickup surface of the imaging device, a lightflux of oblique incidence can be guided to an light-receiving section ofeach pixel efficiently, because the color filter and theonchip-microlens-array are shifted greater toward an optical axis of animage pickup lens at the position which is closer to a peripheralportion of the image pickup surface. Owing to this, shading generated onthe solid-state image pickup element can be controlled to be small. Thepresent examples provide design examples in which the above designrequirement is lighten but further downsizing is aimed.

REFERENCE SIGNS LIST

-   10 Image pickup lens-   50 Image pickup apparatus-   51 Image pickup element-   52 Substrate-   53 Casing-   55 Lens frame-   100 Cell phone-   L1 First lens-   L2 Second lens-   L3 Third lens-   L4 Fourth lens-   L5 Fifth lens-   S Aperture stop-   I Image pickup plane-   F Parallel flat plate

The invention claimed is:
 1. An image pickup lens for forming an imageof a subject onto a photoelectric conversion section of a solid-stateimage pickup element comprising an image pickup surface with a diagonallength 2Y, the image pickup lens comprising, in order from an objectside thereof: a first lens with a positive refractive power, comprisinga convex surface facing the object side; a second lens with a negativerefractive power, comprising a concave surface facing an image side; athird lens comprising an aspheric surface; a fourth lens with a positiverefractive power, comprising a convex surface facing the image side; anda fifth lens with a negative refractive power, wherein an image-sidesurface of the fifth lens has an aspheric shape, and includes aninflection point at a position excluding an intersection point with anoptical axis, and the image pickup lens satisfies the followingconditional expressions:20<ν1−ν2<70  (4)L/2Y<1.1  (10) where ν1 is an Abbe number of the first lens, ν2 is anAbbe number of the second lens, and L is a distance along the opticalaxis from a lens surface arranged at a closest position to the objectside in a total system of the image pickup lens to a focal point at theimage side.
 2. The image pickup lens of claim 1, satisfying thefollowing conditional expression:0.9<f12/f<2.0  (1) where f12 is a composite focal length of the firstlens and the second lens, and f is a focal length of a total system ofthe image pickup lens.
 3. The image pickup lens of claim 1, satisfyingthe following conditional expressions:−2.5<f2/f<−1.0  (2)0.3<r4/f<0.7  (3) where f2 is a focal length of the second lens, r4 is acurvature radius of an image-side surface of the second lens, and f is afocal length of a total system of the image pickup lens.
 4. The imagepickup lens of claim 1, satisfying the following conditional expression:1.60<n2<2.10  (5) where n2 is a refractive index of the second lens ford-line.
 5. The image pickup lens of claim 1, satisfying the followingconditional expression:−2.35<Pair23/P<−0.75  (6) where P is a refractive power of the totalsystem of the image pickup lens, and Pair23 is a refractive power ofso-called an air lens formed by an image-side surface of the second lensand an object-side surface of the third lens, wherein the refractivepower is a reciprocal of a focal length and the value of Pair23 iscalculated by the following expression (7):Pair23={(1−n2)/r4}+{(n3−1)/ r5}−{(1−n2)·(n3−1)·d23/(r4·r5)}  (7) wheren2 is a refractive index of the second lens for d-line, n3 is arefractive index of the third lens for d-line, r4 is a curvature radiusof the image-side surface of the second lens, r5 is a curvature radiusof the object-side surface of the third lens, and d23 is an air distancealong the optical axis between the second lens and the third lens. 6.The image pickup lens of claim 1, satisfying the following conditionalexpression:0.2<d456/f<0.4  (9) where d456 is a distance along the optical axisbetween an image-side surface of the second lens and an object-sidesurface of the fourth lens, and f is a focal length of a total system ofthe image pickup lens.
 7. The image pickup lens of claim 1, wherein anobject-side surface of the third lens is formed in an aspheric shapewhich curves to be closer to the second lens at a position on thesurface, as the position advances toward a peripheral portion.
 8. Theimage pickup lens of claim 1, wherein an image-side surface of thesecond lens is formed in an aspheric shape having negative refractivepower which becomes smaller at a position on the surface, as theposition becomes more distant from an optical axis toward a peripheralportion.
 9. The image pickup lens of claim 1, wherein an image-sidesurface of the fourth lens is formed in an aspheric shape havingpositive refractive power which becomes smaller at a position on thesurface, as the position becomes more distant from an optical axistoward a peripheral portion.
 10. The image pickup lens of claim 1,further comprising an aperture stop which is arranged at a positionbeing closer to the image side than a position on the optical axis of anobject-side surface of the first lens and being closer to the objectside than a position in a most peripheral portion of the object-sidesurface of the first lens.
 11. The image pickup lens of claim 1, whereineach of the first through fifth lenses is formed of a plastic material.12. An image pickup apparatus comprising: a solid-state image pickupelement for photo-electrically converting an image of a subject; and theimage pickup lens of claim
 1. 13. A mobile terminal comprising the imagepickup apparatus of claim
 12. 14. The image pickup lens of claim 1,satisfying the following conditional expression:1.5<|f3|/f<20.0  (8) where f3 is a focal length of the third lens. 15.The image pickup lens of claim 1, wherein the second lens is a meniscuslens.
 16. The image pickup lens of claim 1, wherein the first lenscomprises an aspheric surface.
 17. The image pickup lens of claim 1,wherein there is a surface distance on the optical axis between each ofthe first to fifth lenses.
 18. The image pickup lens of claim 1, whereinthe second lens comprises an aspheric surface.
 19. An image pickup lensfor forming an image of a subject onto an image pickup surface of asolid-state image pickup element where a diagonal length of the imagepickup surface being 2Y , the image pickup lens comprising, in orderfrom an object side thereof: a first lens with a positive refractivepower, comprising a convex surface facing the object side; a second lenswith a negative refractive power, comprising a concave surface facing animage side; a third lens comprising an aspheric surface; a fourth lenswith a positive refractive power, comprising a convex surface facing animage side; a fifth lens with a negative refractive power, wherein thereis a surface distance on the optical axis between each of the first tofifth lenses; the second lens comprises an aspheric surface; an imageside surface of the fourth lens is formed in an aspheric surface havingpositive refractive power which becomes smaller at a position on thesurface, as the position becomes more distant from an optical axistoward a peripheral portion, an image-side surface of the fifth lens hasan aspheric shape, and includes an inflection point at a positionexcluding an intersection point with an optical axis, and the imagepickup lens satisfies the following conditional expressions:20<ν1−ν2<70  (4)L/2Y<1.1  (10) where ν1 is an Abbe number of the first lens, ν2 is anAbbe number of the second lens, and L is a distance along the opticalaxis from a lens surface arranged at a closest position to the objectside in a total system of the image pickup lens to a focal point at theimage side.